How reliable are ecgs? my pre-op one showed anterior infarction and dr thought it showed afib.

Great question &: Example. The false positive anterior mi is not uncommon in women due to breast tissue attenuation effects & these computer algorithms while sophisticated & often accurate have pitfalls. The human mind learns this pitfalls over time so we aren't tricked by them but still in cases like this an echocardiogram may needed to prove positivity.